This proposal is for continuation of our work investigating the etiology and pathogenesis of important hormonally-responsive tumors using epidemiologic studies supported by relevant clinical endocrinologic investigations. For years 07-09 of grant CA-15104, we propose to continue surveillance of a cohort of women, who have prospectively recorded detailed menstrual cycle patterns and reproductive events, for incident breast cancers. This is to determine if special antecedent patterns and events can be elucidated which are predictive of breast cancer and also yield clues to hormonal defects. In this cohort, we also plan to identify women with hysterectomy, obtain clinical and pathologic records, and correlate cycle patterns with benign uterine myomas. We also propose a case-control to further explore the etiology and pathogenesis of uterine myomas, an important cause of surgery and female morbidity in the U.S.A. Variables to be studied include menstrual and reproductive events implicated in breast, endometrial and cervical cancer, the use of medications including gonadal hormones and other drugs affecting prolactin secretion or the pituitary-ovarian axis, demographic and occupational features, and related systemic morbid events. It is further proposed to explore our "anovulatory hypothesis" among selected patients with myomatous disease in the case-control study. Differential levels of estrogen and progesterone receptors will be sought in tumor tissue and control myometrial tissue. Further, to explore the possibility of luteal phase inadequacy among these patients, manifested by subnormal serum progesterone compared to estrogen levels, basal body temperatures and serum steroid hormone and gonadotropin levels be done through a menstrual cycle in a group of women with myomatous disease and an appropriate control group.